[Multiparticulate systems in the controlled release of active substances in the gastrointestinal tract]

The design of multiparticulate systems as carriers for molecules that have to be delivered at specific sites of the gastrointestinal tract must take into account the common events that govern this region. The intrusion of the multiparticulate systems has to face, by meanings of synthesis methods, or only by lack of aggressiveness the host system defences. Thus, non-specific and specific defence mechanisms are deployed to deal with the intruding material. Several strategies can be mentioned, as (a) prevent the contact and remove if contacted (b) kill if not remove, by the micro-fold cells that engulf bacteria and the gastrointestinal-associated lymphoid tissue. A physical barrier that adheres, prevents the contact, en-traps and removes the foreign matter is the mucus produced by the goblet cells.